Method of cutting an elongated tube and apparatus therefor

ABSTRACT

A MACHINE HAVING MEANS FOR GUIDING AND INTERMITTENTLY ADVANCING AN ELONGATED, TUBULAR ELEMENT A PREDETERMINED DISTANCE ALONG A PATH, AND FOR GRIPPING TWO SPACED PORTIONS OF SAID ELEMENT AND SEPARATING THEM FOLLOWING EACH ADVANCEMENT THREOF. A CUTTING DEVICE ON THE MACHINE INCLUDES AN ANNULAR CUTTING MEMBER WITH A RADIALLY INNER CUTTING EDGE THROUGH WHICH THE ELEMENT IS SLIDEABLY RECEIVED DURING SAID ADVANCEMENT THEREOF. ACTUATING MEANS EFFECTS MOVEMENT OF THE CUTTING MEMBER IN AN ECCENTRIC PATH AROUND THE TUBULAR ELEMENT WHEREBY THE CUTTING OPERATION IS PERFORMED , AFTER WHICH THE SEVERED PORTION OF THE TUBE IS BENT AND EJECTED FROM THE MACHINE.

March 9, 1971 Filed Nov. 25, 1968 A Z`lss 2. DZ,

N. A. FRANKS METHOD OF .CUTTING AN ELONGATED TUBE AND APPARATUS THEREFOR13 Sheets-Sheet l INVENTOR.

i March 9, 1971 N. A. FRANKs METHOD OF CUTTING AN ELONGATED TUBE ANDAPPARATUS THEREFOR Filed NOV. 25,

13 Sheets-Sheet 2 N. A. FRANKS March 9, 1971 METHOD OF' CUTTING ANELONGATED TUBE AND APPARATUS THEREFOR Sheets-Sheet 5 Filed Nov. 25, 1968INVENTOR, /I/[l//ELA A. HWI/VM? BY March 9., 1971 N. A. FRANKS METHOD OFCUTTING AN ELONGATED TUBE AND APPARATUS THEREFOR N. A. FRANKS March 9,1971 METHOD OF CUTTING AN ELONGATED TUBE AND APPARATUS THEREFR FiledNOV. 25, 1968 13 Sheets--Sheet 5 INVENTOR. /l/[WHL ,4. FPA/Wm March 9,1971 N. A. FRANKs 3,568,488

METHOD OF CUTTING AN ELONGATED TUBE AND APPARATUS THEREFOR Filed Nov.25. 1968 13 Sheets-Sheet 6 w vw@ Q ONK N- A. FRANKS March 9, 1971 METHODOF CUTTING AN ELONGATED TUBE AND APPARATUS THEREFOR Filed Nov. 25', 196s13 Sheets-Sheet 7 INVENTOR. /w/az. A, /z//ff N. A. FRANKS y March 9,1971 y METHOD oF CUTTING AN ELUNGATED TUBE AND APPARATUS THEREFoR FiledNov. 25, 1968 13 Sheets--Sheet 8 OQUQ Arme/1MM March 9, 1971 N. A.FRANKs 3,558,433

METHOD 0F cUTTIN@ AN ELONGATED TUBE AND APRA'Tus THEREFOR Filed Nov. 25,1968 13 Sheets--Sheet 9 BY 12M@ @M/ March 9, 1971 N. A. FRANKS METHOD 0FCUTTING AN ELONGATED TUBE AND APPARATUS THEREFOR Filed Nov. 25. 19,68

13 Sheets--Sheet I10 March 9, 1971 A N. A. Plumes 3,568,438

METHOD OF' CUTTING AN ELONGATEDTUBE AND APPARATUS THEREFOR Filed Nov.25, 196s y 13 Sheets-sheet 11 won m34 87 o@A @o I NVENTOR. H6. Z ,Vm/mA. Pfff/vw AUDE/ME75 March 9, 1971 N. A. FRANKs METHOD OF' CUTTING ANELONGATED TUBE AND APPARATUS THEREFOR Filed Nov. 25, 1968 13Sheets-Sheet 12 ammi Q65, .mw .dl/Ud.

SSG o@ HmUlli QS* www. 5N QQ @lip 01| Nw QQ @BZW/6%@ March 9, 1971 N. A.FRANKS 3.568538 METHOD oF CUTTING AN ELONGATED TUBE ANnAPPARATusTHERETOR Filed Nov. 25, 1968 1,5 Sheets-Sheet 15 RNN m,

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United States Patent O Mice 3,568,488 METHOD F 'CUTTING AN ELONGATEDTUBE AND APPARATUS THEREFOR Newell A. Franks, Fawn River Township, St.Joseph County, Mich., assignor to Burr Oak Tool & Gauge Company,Sturgis, Mich.

Filed Nov. 25, 1968, Ser. No. 778,611 Int. Cl. B21b 21/00; B21d 28/00;B26f 3/00 US. Cl. 72-68 8 Claims ABSTRACT 0F THE DISCLOSURE A machinehaving means for guiding and intermittently advancing an elongated,tubular element a predetermined distance along a path, and for grippingtwo spaced portions of said element and separating them following eachadvancement thereof. A cutting device on the machine includes an annularcutting member with a radially inner cutting edge through which theelement is slideably received during said advancement thereof.Actuatin-g means effects movement of the cutting member in an eccentricpath around the tubular element whereby the cutting operation isperformed, after which the severed portion of the tube is bent andejected from the machine.

BACKGROUND OF THE INVENTION This invention relates in general to amethod and apparatus for cutting a long length of tubular stock intorelatively small, preselected lengths and bending said lengths intoU-shaped members. More particularly, the invention relates to animproved method and cutting device adapted to a machine for bending theU-shaped tubular members which are assembled with plural parallel iinsto form heat exchange units.

Persons familiar with the operation of tube cutting and tube bendingmachinery have long been aware of the need for a method and apparatusfor cutting tubular stock, such as the copper pipe used in coolingcoils, whereby to avoid the radially inwardly projecting burr, which haspreviously been formed at each cut, and to reduce the amount ofmaintenance required to keep the cutting device of the apparatus incompletely satisfactory cutting condition. Heretofore, it has beencommon practice to use cutting members which are orbited around thetubular element in order to effect the cutting thereof. This arrangementcreated complicated and costly maintenance problems resulting from thecomplicated mechanism required to effect movement of the cuttingmembers. Moreover, this type of equipment forms a radially inwardlyprojecting burr on the pipe adjacent the cut.

While the embodiment of the invention disclosed herein for illustrativepurposes is adapted for use with a bending machine, it will berecognized that specific reference to the bending machine and thearticles produced thereby is not intended to limit the scope orapplicability of the invention.

Accordingly, a primary object of this invention is the provision of amethod for cutting a portion of a metal tube from a length thereof Whileminimizing the amount of radially inwardly projecting burr formed at thecut, said method being adapted for simultaneously cutting a plurality oftubes, both quickly and accurately.

A further object of this invention is the provision of a cutting devicefor carrying out said method, wherein said device is inexpensive tooperate, requires a minimum of maintenance, operates completelyautomatically and can be adapted for use on existing machines in which atubecutting and bending operation must be performed.

Patented Mar. 9, 1971 Other objects and purposes of this invention willbecome apparent to persons familiar with this type of equipment uponreading the following speciiication and examining the accompanyingdrawings, in which:

FIG. l is a schematic side View of a machine embodying the invention andarranged for advancing, cutting and bending one or more tubularelements.

FIG. .2 is a top view including the cutting and bending components ofsaid machine.

FIG. 3 is a perspective view of the top and front side of the cuttingand bending components of said machine.

FIG. 4 is a perspective view of the rear side of the cutting componentof the machine.

FIG. 5 is a side elevational view of the cutting component and part ofthe bending component of said machine.

FIG. `6 is an enlarged fragment of the structure appearing in FIG. 2.

FIG. 7 is a sectional view taken along the line VII- VII in FIG. 6` withthe bend arbor rotated 180 degrees.

FIG. 8 is an enlarged sectional view taken along the line VIII--VIII inFIG. 5.

FIG. 9 is a sectional view taken along the line IX-IX in FIG. 8.

FIG. 9A is an enlarged, modified fragment of FIG. 9.

FIG. 10 is a sectional view substantially as taken along the line X-X inFIG. 8.

FIG. 11 is an enlarged fragment of FIG. 9 showing a cutting tool.

FIG. 12 is a sectional view substantially as taken along the lineXII-XII in FIG. 6l.

FIG. 13 is an enlarged sectional view taken along the line XIII- XIII inFIG. 9.

FIG. 14 is a sectional view taken along the line XIV- XIV in FIG. 5.

FIG. 15 is a fragment of a top plan view of an alternate tube cuttingcomponent embodying the invention.

FIG. 16 is an elevational view of the output end of said alternatecutting component.

FIG. 17 is a sectional view taken along the line XVII- XVII in FIG. 15.

FIG. 18 is an enlarged fragment of FIG. 17.

FIG. 19 is an enlarged sectional view taken along the line XIX-XIX inFIG. 15

FIG. 20 is a sectional view taken along the line XX- XX in FIG. 19.

FIG. 21 is a sectional view taken along the line XXI- XXI in FIG. 19.

FIG. 22 is a perspective view of the annular member in the eccentricmechanism.

FIG. 23 is a perspective view of the cam in said eccentric mechanism.

FIG. 24 is a perspective view of the stub shaft in said eccentricmechanism.

FIG. 25 is a sectional View taken along the line XXV- XXV in FIG. 19.

FIG. 26 is an enlarged sectional view taken along the line XXVI-XXVI inFIG. 17.

FIGS. 27 and 27A disclose in two parts a schematic diagram of theelectrical circuit of the apparatus embodying the invention.

For convenience in description, the terms upper, 1ower, front, rear andwords of similar import will have reference to the machine embodying theinvention as appearing in FIGS. 1 and 5 which disclose the front side ofthe machine. The terms input or entry and output or exit will havereference to the left and right ends, respectively, of the machine asappearing in FIGS. 1 and 2. The terms inner, outer and derivativesthereof will have reference to the geometric center of said machine andthe components thereof.

3 SUMMARY oF THE INVENTION The objects and purposes of the invention,including those set forth above, have been met by providing a method andapparatus for feeding one or plural pieces of elongated tubular stockthrough a cutting device, gripping the stock on both sides of thecutting device and then urging the gripped portions in oppositedirections away from the cutting device while causing said device tomake a circular cut in the external surface of the tubular stock betweenthe points at which it is gripped. The cutting device has an annularcutting tool with a radially inwardly extending cutting edge which isurged against the surface of the tubular stock while the axis of thecutting edge is moved in an increasing eccentric path around the axis ofthe tubular stock being cut.

The cutting device is mounted upon and cooperates with mechanism foradvancing the tubular stock from a supply thereof, as on a drum, throughthe cutting device so that predetermined lengths of the tubular stockwill be cut automatically. After the cutting operation is performed, thepredetermined lengths of the tubular stock are bent into U-shapedmembers and discharged from the machine.

DETAILED DESCRIPTION The method of the invention will be disclosed byreference to and in terms of a preferred apparatus by means of which themethod can be carried out. The broad concept of feeding, cutting andbending tubular stock by an I automatically controlled machine is old inthe art and. in fact, the basic structures of the feeding and bendingcomponents disclosed hereinafter have been used previously inassociation with a different type of cutting device. However, certainnovel modifications have been made in these components. particularly inthe electrical controls thereof, to adapt them to the cutting devicewhereby to provide an improved method of tube cutting which involvescoordinated performance by the feeding and bending components.

The machine selected to illustrate and embody the invention, as shown inFIG. l, has a tube supply reel at the input end thereof. Broadlyspeaking, one or more tubes 11. which are supported by the reel l0 orseveral coaxial and adjacent reels, are intermittently pulled throughrollers 12 of the tube straightening unit 13 by and between adjacentreaches of the endless belts 14 and 15 of the tube drive 17. The tube ortubes are then fed through the tube position detector 16 into the fixedtube guide 18 and thence into the movable tube guide 19, these twoguides being supported by the reciprocating carriage or slide 22 whichis supported on the bed 21 immediately upstream of the tube cutting head23. The tube drive 17 and bed 21 are both mounted upon the table 24,supported by base frame 20.

The tube or tubes 11 are fed through the cutting head 23 into the tubeguide pipes 26, which are attached to and movable with the pivotedmember 25 of the tube bending unit 32. Said bending unit 32 includes apair of axial support members 27 and 28 which project upwardly from theframe 29 and pivotally support the member 25 for movement around ahorizontal axis transverse of the machine (FIG. 6). A tube clamp 33,which receives and guides the tubes 11 from the guide pipes 26, is alsosupported on the member 25 downstream of said pipes to hold them whilethey are being bent.

The structures and operation of the supply reel 10, the straighteningunit 13 and the tube bending unit 32 may be conventional. Thus, furtherdetailed description of these parts is believed unnecessary to disclosethe structure and process of the invention.

The tube drive 17 (FIG. l) includes a frame 36 from which four parallelshafts extend sidewardly in a rectangular pattern to support the pulleys37, 38, 39 and 40. around which the belts 14 and l5 extend. The adjacentreaches 43 and 44 0f the belts 14 and 15 respectively, are

positioned so that they tightly enage opposite sides of the tubes 11which pass between and lengthwise of said reaches. The pulleys aredriven by means including the motor 45 (FIG. 2) acting through a drive46 so that the reaches 43 and 44 are both urged rightwardly, asappearing in FIG. l, during a feeding operation. However, after thefeeding operation has been performed, and at a later stage in thecutting process, the reaches 43 and 44 are urged leftwardly (FIG. l) byan appropriate signal to apply a tension to the tubes 11.

The tubes 11 are advanced by the tube drive 17 into the fixed guide 18which, as shown in FIGS. 3 and 5, is comprised of a pedestal 47 which ismounted upon the bed 21 and supports a guide block 49. Said block 49 hasa plurality of parallel channels 52 in which the tubes 11 are snugly andslideably received and which are covered by a preferably transparentplate 53. The cover plate 53 and guide block 49 are held with respect toeach other and upon the pedestal 47 by a pair of crossbars 54 which aresecured to the upper ends of the pedestal 47 and extend across the coverplate 53.

The reciprocating slide 22, which supports the movable tube guide 19(FIGS. 3 and 5), is supported along its lengthwise edges (FIG. 13) bysuitable ways 56 and 57 which in turn are mounted upon the output end ofthe bed 21. Rightward movement (FIG. 6) of the carriage 22 is adjustablylimited by engagement of the stud on the left end of the carriage 22with a block 51 (FIG. l2) on the table 24.

The movable guide 19 has a guide block 58 with a plurality of tubereceiving channels 59 which are axially aligned with the channels 52 andare covered by a transparent plate 62 held in place upon the guide block58 by the clamp bar 63. The output end of the guide block S8 issupported by a guide support 60 (FIG. 9) mounted upon the slide 22 andheld in the position by a clamp bar 61.

The slide 22 is reciprocated by a hydraulic cylinder 66 (FIG. 5) whichis supported at its rightward end by a pedestal 65 and which has anactuating rod 67 anchored at its outer end in the block 68 (FIG. 9)secured upon the slide 22.

A mounting plate 71 (FIGS. 3, 9 and 13) is rigidly secured in an uprightposition to the output end of the slide 22 and has a horizontallyelongated opening 72 (FIG. l0) for receiving the tubes projected fromthe movable guide 19. The cutting head 23 has input and output sideplates 73 and 74. respectively, which are preferably circular andsubstantially identical in size and shape. The input side plate 73 ismounted upon, and rigidly held against relative radial movement withrespect to, the mounting plate 71 by means including the pins 77.

The side plates 73 and 74 are held against movement away from each otherand are further secured to the mounting plate 71 by means including aplurality of bolts 78 (FIG. 9) which are threadedly enaged with themounting plate 71. Each bolt 78 is embraced by an inner sleeve 79, oneend of which is threadedly engaged within an appropriate threadedopening in the front side plate 73. The opposite end of the sleeve 79 isexternally threaded and extends beyond the exit side plate 74 where itis engaged by a nut 82. Thus, the side plates 73 and 74 are also heldagainst movement away from each other by the sleeve 79 and nut 82.

A pair of bearing plates 83 and 84 (FIG. 9) are snugly disposed withinrecesses 86 and 87, respectively, in the opposing faces of the sideplates 73 and 74. The bearing plate 83, for example, has an opening 88which snugly embraces the inner sleeve 79. The bearing plate 84 has anopening 89 which snugly embraces and receives an outer spacing sleeve 92which engages and extends between the opposing faces of the bearingplate 83 and the axial wall 91 of recess 87. Thus, the spacing betweenthe side plates 73 and 74 is positively controlled by the thickness ofbearing plate 83 and the length of the plural outer sleeves 92.

A movable cutting tool support 93 (FIGS. 9 and 1l), which is preferablycircular, is slidably disposed between and of approximately the samediameter as the bearing plates 83 and 84. The cutting tool support 93 iscomprised of a center plate 94 and a pair of slide plates 96 and 97which are held in coaxial positions and `against relative radialmovement by anged sleeves 98 which extend through appropriate openingsin the plates 94, 96 and 97, and whose axial ends are flush with theouter sides of the plates 96 and 97.

The plates 94, 96 and 97 have axially aligned openings (FIG. 9) whichtogether define an axial passageway 99 through the cutting tool support93 in which the outer sleeve 92 is loosely disposed. That is, thepassageway 99 permits relative radial movement of the tool support 93with respect to the sleeve 92 hence with respect to the bearing plates83 and 84. 'I'he center plate 94 (FIG. 9) has a plurality (here live) ofopenings 102 aligned along the horizontal axis of the plate and in eachof which a cylindrical tool 103 is snugly but slideably disposed. Theslide plates 96 and 97 have openings 104 and 105, respectively, whichare coaxial with and somewhat smaller than the opening 102 so that saidplates engage the opposite ends of the tool 103. Said openings 104 and105 are also somewhat larger than the outside diameter of the tube 11 sothat the tube 11 can be inserted therethrough and to allow for relativeradial movement of tool support 93 with respect to tube 11 during acutting cycle.

Each tool 103 (FIG. 1l), of which there are ve in this particularembodiment, has an integral, and radially inwardly projecting, annularcutting edge 107 which is slightly larger in inside diameter than theoutside diameter of a tube 11 and somewhat smaller than the diameters ofthe openings 104 and 105. One or more tools 103 can be removed andreplaced merely by separating the slide plate 97, for example, from thecenter plate 94, after which the tool can then be removed from theopening 102.

The entry side plate 73 (FIG. 11) and adjacent bearing plate 83 areprovided with plural pairs of coaxial sleeve openings 108 and 109,respectively, in which a flanged guide sleeve 112 is snugly received.The guide sleeve 112 has an inside diameter slightly larger than theoutside diameter of the tube 11 and serves to guide the tube through thecylindrical tool 103 in the tool support 93.

A plurality of flanged sleeves 113 (FIG. 9) are snugly received intocoaxial pairs of openings 114 and 115 in the exit side plate 74 and exitbearing plate 84, respectively, and said flanged sleeves 113 arepreferably identical with and axially aligned with the flanged sleeves112, for the purpose of guiding the tube 11 as it departs from thecutting tool support 93. Thus, as shown in FIG. l0, there are ve each ofthe flanged sleeves 112 and 113 for handling ve tubes 11 at the sametime in this particular embodiment. The sleeves 112 and 113 slideablyembrace those portions of the tubes 11 adjacent to the opposite sides ofthe tool support 93 to hold said portions against radial movement duringthe cutting operation discussed hereinafter.

The entry side plate 73 and entry bearing plate 83 are provided with aplurality of axially aligned openings |117 and 118 (FIG. 9) in which theflanged pin sleeves 119 are snugly received. Each pin sleeve 119 (ofwhich there are six in this embodiment) is axially alignable with, andof approximately the same inside diameter as, one of the flanged sleeves98. Each of six lock pins 122 supported upon an upright lock plate 123(FIG. 9) slideably extends into each sleeve 119.

Each lock pin 122 has a tapered tip 124 corresponding to the taperedopening 125 in the flanged sleeve 98. As the pins 122 are withdrawn fromflanged sleeve 98, the cutting tool plate support 93 is permitted totravel eccentrically, being driven from support ring 141, throughsprings 142 connected to the tool plate support 93. The greater theamount of withdrawal of the pins 122, the

CII

greater the eccentricity of the tool plate support 93, hence, the cutter103 with respect to the tube element 11.

The lock plate 123 has a horizontally elongated opening 126 (FIGS. 9 and13) through which the tubes 11 can freely move as they pass from themovable guide block 58 to ,the tube cutting head 23. The lock plate 123is secured at its lower end upon a slide 127 which is in turn engagedalong its opposite edges by the guides 128 and 129 secured to the lowersurface of the slide 22. A block 130, which is mounted on the lower sideof slide 127, is secured to the free end of the actuating rod 132 (FIG.9) of a pressure fluid actuated cylinder 133 secured to the carriage 22.Thus, the cylinder 133 can reciprocate said slide 127, hence, the lockplate 123, whereby the lock pins 122 are moved axially of the sleeves98.

Rightward movement (FIG. 9) of the slide 127 relative to carriage 22 islimited by engagement of the enlargements 134 on the lock pins 122 withthe anged faces of the pin sleeves 119. Leftward movement of the slide127 relative to the carriage 22 is adjustably limited by engagementbetween the lock nuts 136 on the screw 137 and the rightward face of theanchor block 68 on the carriage 22. The rightward end of the screw 137is secured to the slide 127 and the left end of the screw i137 isslideably receivable into an opening 138 in the block 68.

The cutting tool support 93 (FIG. 9) is resiliently suspendedsubstantially coaxially within the support ring 141 by a plurality ofsprings 142, and the inner edge of the ring 141 is disposed between theside plates 73 and 74. The inner end of each spring 142 engages a screweye 143 which is threadedly anchored in the circumferential edge of thecenter plate 94 or is inserted in a hole provided in the outercircumference of plate 94 (FIG. 9A). The outer end of each spring 142 isengaged with a screw eye 144, the shank of which extends through aradial opening 146 in the ring 141 for threaded engagement at its outerend by a nut 147. Thus, tension on each spring 142 can be altered asrequired by tightening or loosening the nuts 147 on the screw eyes 144.Studs 148 and 149 are threadedly received through openings 152 and 153,respectively, and engaged by lock nuts 154 and 155 for engaging andthereby spacing the ring 141 with respect to the side plates 73 and 74,axially thereof.

The support ring 141 (FIG. 14) has a pair of diametrically disposed,integral projections 157 and 1158 in which bearings 159 and 160 aredisposed for engagement with the eccentric ends 163 and 164 of theshafts 168 and 169 (FIG. 10) supported b'y the bearing structures 166and 167, respectively, which are mounted upon the reciprocating carriage22 leftwardly of the tube cutting head 23 (FIG. 6). Pulleys 172 and 173,which are mounted on shafts 168 and 169, are engaged by an endless belt174 for simultaneous rotation of said shafts. The shaft 168, in thisembodiment, is coaxially coupled with the shaft 176 of the hydraulicmotor 177 supported upon the carriage 22 for driving the shafts 168 and169, whereby eccentric motion is imparted to the support ring throughthe suspending springs 142 and then to the cutting tool support 93 heldthereby to perform the cutting operation. The motor 177 is connected toconduits 178 and 179 for conducting pressure fluid from a source (notshown) to the hydraulic motor and return.

While a variety of devices may be used to sequence automatically thefunctions of tube cutting head and the related components, a preferredsystem therefor is discussed for illustrative purposes and, at the sametime, the functioning of the system will be set forth with reference toFIGS. 27 and 27A. Specifically, as the tubes 11 are moved through thecutting head 23, through the tube clamp 33, and onto the mandrels 180 ofthe bending machine, they ultimately engage the stripping sleeves 181telescoped on the mandrels 180. The sleeves 181 are, accordingly movedrightwardly (FIG. 2) at a relatively fast rate until the crosshead 182connected to said sleeves 181 operates switch 183 which decelerates therotational speed of motor 4S, hence, the advancement speed of the tubedrive. Shortly thereafter, the crosshead 182 engages switch 184 whichde-energizes the drive motor 45, and closes the tube clamp 33. Operationof pressure switch 194 (FIG. 27) operates cylinder 133 to retract thepins 122 leftwardly (FIG. 2) and energizes motor 177 whereby the cuttinghead 23 is caused to move in an annular path around each tube 11.

Switch 186 is operated by the cam 185 on the lock plate 123 when thepins 122 are fully withdrawn from their locked positions.

A switch 187 (FIG. 2) is mounted on the table 24 for engagement by thedrive 46 and for operation only when the reaches 43 and 44 (FIG. l) aremoved leftwardly by the motor 45. Such operation de-energizes the motor45 and the motor 177. Also, operation of switch 187 retracts thecylinder 66 (FIG. 6) whereby the carriage 22 is moved leftwardly untilit operates switch 188 mounted on the the bed 21.

Operation of switch 188 extends the hydraulic cylinder 189 (FIG. 4)whereby the output end of the table 21 is pivoted upwardly around theinput end thereof. The switch 191 secured to the base frame 20 isoperated by the actuator connected to the table 24 when said tablereaches its raised position. Switch 188 also initiates the bendingmovement of the pivoted member 25 whereby the cut portions of tube 11are bent into U-shaped pieces.

The bending movement of the member 25 (FIG. 2) is effected by a pair ofracks 192 and 193, which are mounted on the frame 29 for lengthwisemovement thereof. Said racks engage gears (not shown) connected to themember 25 concentrically with the pivot axis thereof. The racks 192 and193 move leftwardly (FIG. 2) to bend the tubes until the rack 193engages switch 195 which is mounted on frame 29 and retracts themandrels 180. The switch 204 is tripped by the retraction of themandrels and releases the clamp 33 and terminates the rack movement.Switch 204 also actuates means, such as a power cylinder and appropriatelinkage (not shown), whereby the stripping sleeve 181 are urgedleftwardly to discharge the bent tubes from the bending unit 32 into thechute 197 below the cutting head 23.

Switch 198 (FIG. `2) is operated when the stripping sleeves 181 reachtheir fully extended or leftward positions whereby their rightwardreturn is effected, providing switch 196 is cleared. Switch 196 is asafety check. Providing all tubes 11 are discharged, the switch 196allows the stripping sleeves to return. If any or all of the tubes arenot discharged, switch 196 stops the automatic cycle of the machine.Switch 199 is operated just before the stripping tubes are fullyretracted and effects a reduction in the speed of their retractionmovement. Thereafter, switch 202 is operated whereby the retraction ofthe stripping tubes is terminated.

Movement of the mandrels 180 is effected toward and away from thebending unit 32 by power linkage means (not shown) supported on theframe 29.

Mandrel movement toward the unit 32 is initiated by a pressure switch194 (FIG. 27) when the clamp 33 iS is closed. Operation of switch 19S bythe rack 193 initiates return or retracting movement of the mandrels180. Switch 204, which is in series with switch 191, is closed when themandrels return to their rightward or retracted positions, whereby theclamp 33 is released. Closure of switch 198 also causes the racks 192and 193 to return the pivoted member 25 to its original position of FIG.3. In so doing, rack 193 closes switch 206 whereby hydraulic cylinder189 is caused to lower the table 24. Since carriage 22 is in theretracted or leftward position, and due to the condition of switches 206and 202, another cycle of operation will commence with rightwardmovement of the carriage 22 and of the tubes 11.

Switch 207 (FIGS. l and 22) is mounted upon the table 24 (FIG. l) sothat it is operated to de-energize sublil) stantially the entireelectrical system of the machine if the detector 16 is shorted out by amisaligned tube 11 passing from the tube drive 17 to the xed guide 18.The detector 16 has a pair of spaced bars 211 and 212 which extendtransversely of, above and below, the tubes 11 between the drive 17 andguide 18. The bars 211 and 212 are supported upon a post having a baseplate mounted upon the table 24 and operably connected to said switch207. Said bars 211 and 212 are spaced slightly from the tubes 11 whenthey are properly aligned with or Within the channels 52.

A pump switch 213 (FIGS. 27 and 27A), start switches 214, 215 and 216and a master switch 217 must be closed to energize the electrical systemof the machine. Stop switches 221, 222 and 223 are provided for theindicated purposes.

OPERATION While the operation of the above-described apparatus and theportions thereof comprising the invention will be apparent to personsskilled in this art from such description, a brief summary thereof willnow bet set forth.

Starting with the carriage 22 in its retracted or leftward position ofFIGS. l, 2 and 3, the plural tubes 11 are manually fed from the supplyreel 10 through the tube straightening unit 13 and into the tube drive17. Accordingly, when the various start switches 213 through 217,inclusive (FIG. 27), are closed, the drive motor 4S will be energizedwhereby the tubes 11 will be fed through the fixed guide 18, the movableguide 19, the tube cutting head 23, the tube guide pipes 26, the tubeclamp 33 and thence onto the mandrels 180. At the same time, thecarriage 22 will be moved rightwardly or extended into its rightwardposition of FIG. 5 where the cutting head 23 is relatively close to theguide pipes 26. During the rightward movement of the tubes, they willengage the stripping sleeves 181 and move them rightwardly until suchmovement causes the crosshead 182 to close switch 183 and therebydecelerates the drive motor 45, hence, the belts 14 and 15, thencrosshead closes switch 184 which stops drive motor 45, hence, the belts14 and 1S. Switch 184 closes clamp 33 which energizes pressure switch194 causing the mandrels 180 to be moved leftwardly, whereby to givemaximum support to the nonmoving part of the tube during the subsequentbending operation.

Closing pressure switch 194 causes the hydraulic cylinder 133 to operateand to effect the retraction or leftward movement of the lock pins 122,closing of the switch 194 also causes the motor 45 to rotate in theopposite direction from its normal feed rotation. whereby the reaches 43and 44 of the tube drive 17 are urged leftwardly, as appearing inFIG. 1. However the tube clamp 33 tightly grips the tubes 11 extendingtherethrough so that the leftward urging of the reaches 43 and 44 putssaid tube under tension. At the same time, the motor 177 is energized,whereby the cutting tool support 93 is urged by the eccentrics 163 and164 acting through the springs 142 and the support ring 141 to move inannular path so that the cutting edge 107 of each cylindrical tool 103vstarts to make an annular cut in the periphery of the tube which itencircles. At some point during the cutting cycle, as the cylindricaltool 103 is making its annular cut in the periphery of the tube andcontinuously penetrating deeper into the wall of the tube, and with thetension applied to said tube 11 by the reaches 43 and 44 of the tubedrive 17, the tensile strength of the tube wall not yet severed isexceeded and the tube breaks.

Consequently, the tube material is not cut entirely through, butpartially cut and partially pulled apart at the cutting point.Therefore, the internal burr is minimized by the extruding caused by thepulling apart action. At the point when the tube breaks, the cylinder133 immediately retracts the remainder of its full travel, whereby cam185 on the lock plate 123 actuates switch 186. The reverse direction ofmotor 45 actuates switch 187, which stops the drive motor 45 and thecuttter motor 177 and causes the cylinder 133 to move the pins 122rightwardly into their locked or extended positions. Retraction of thecarriage 22 closes switch 188 to operate hydraulic cylinder 189 wherebythe output end of the table 24 is raised. Thus, the ends of the tubes 11extending from the cutting head 23 are moved out of positions ofinterference with the guide pipes 26 during the subsequent bendingoperation, and the cutting head 23 is moved out of a position ofinterference until the discharge of the U-shaped pieces from the tubeclamp 33 after the bending operation.

When switch 188 is closed, the pivoted member 25 is moved upwardlyaround the pivot axis thereof by the racks 192 and 193 from its FIG. 3position into its FIG. 7 position. The rack 193 operates switch 195 towithdraw the mandrels, thereby actuating switch 204, which stops thebending operation. Operation of switch 204 also releases the clamp 33from its engagement of the tubes 11, and causes the stripping pipes 181to move leftwardly, as appearing in FIG. 7, to discharge the bent tubesthrough the broken line position thereof and then into the chute 197.Following the discharge of the bent tubes from the mandrels 180, saidstripping plates 181 are returned to their rightward or retractedposition and the pivoted member is pivoted in a counterclockwisedirection as appearing in FIGS. 7 and 1 into its FIG. 2 position byrightward movement of the rack 193. Thus, rack 193 closes switch 206whereby the rightward end of the table 24 is lowered and another cycleof operation will commence immediately with the rightward movement ofthe carriage 22 and the energization of the drive motor -45 whereby thetubes 11 are fed through the cutting head 23, the pipes 26, the tubeclamp 33 and thence onto the mandrels 180, as previously described.

ALTERNATE STRUCTURE The method of the invention may also be practiced bymeans of an apparatus having an alternate tube cutting componentincluding the tube cutting head 23A (FIG. 15) wherein the remainder ofthe apparatus is substantially the same as set forth herein above.Specifically, the carriage 22A may be substantially identical with thecarriage 22 (FIG. 9) and may support a movable tube guide of the typeshown at 19 in FIG. 9. Also, a slide 127A may be secured beneath and tothe carriage 22A for movement by a pressure cylinder 133A also securedto the carriage 22A. However, the lock plate 123 of FIG. 9 is replacedby a horizontally elongated bearing support 230 which is rigidly securedbetween the ends thereof to the rightward side of the slide 127A. A pairof bearing supports 166A and 167A are supported upon the carriage 22Aand in turn support shafts 168A and 169A, respectively. The shaft 168Amay be connected to drive means like the motor 177 shown in FIG. 2. Theleftward ends of the shafts .168A and 169A are interconnected forsimultaneous driving by a pair of pulleys 172A and 173A and a belt 174A.

A pair of bearings 231 and 232 are mounted within appropriate openingsin the bearing supports 230 near the opposite ends thereof, and each ofsaid bearings embraces the X-shaped slide 241 of the identical eccentricmechanisms 233 and 234, respectively, Since the eccentric mechanisms 233and 234 may be and preferably are identical, the mechanism 233 will bedescribed in detail and such description will be understood to apply tothe mechanism 234.

The rightward end of the shaft 168A has a concentric annular flange 236with four uniformly disposed radially opening slots 237. An annularmember 238 (FIG. 22) has four integral segments 240 of a cylinderarranged to define a cylinder and circum-ferentially spaced uniformly todefine four slots 239. Said annular member 238 is secured to the flange236 on the shaft 268A so that said 1U slots 239 are in precise alignmentwith the slots 237 and of substantially the same width, and so that thesegments 240 extend away from the flange 236.

An X-shaped slide 241 (FIGS. 19 and 20) is slideably supported withinthe slots 239 of member 238 for movement lengthwise thereof and for snugembracing by the inner race of the bearing 232. Each of the fourradially extending legs 242 of the slide 241 has a rightwardly openingnotch 243 in the peripheral edge thereof into which the inner race ofthe bearing 231 is received, thereby preventing leftward movement of thebearing with respect to the slide. The bearing 232 is held againstrightward movement with respect to the slide 241 by an X- shapedretainer 244 (FIGS. 19 and 20) secured to the slide 241 by screws 246.Thus, the slide 241 and its retainer 244 can move when so urged by thebearing support 230 and the bearings 231 and 232 between positionsindicated by solid lines and broken lines in FIG. 19.

The rightward side of the slide 241 (FIG. 19) has a recess 247 intowhich the flange 248 (FIG. 23) of a flanged cam 249 is received. Theretainer 244 (FIG. 20) has an elongated opening 252 through which thecam 249 extends rightwardly. Thus, the flanged cam 249 is rigidly heldwith respect to the slide 241 and movable therewith.

A collar 253 (FIGS. 19, 21 and 25) is secured to the annular member 238by bolts 254. Said collar 253 has a substantially rectangular recess 256opening toward said member 238 and defined by a rightward end wall 257(FIG. 25) having an elongated opening 258 which has an enlarged centralportion 259 for reasons appearing hereinafter. The lengthwise ends ofopening 258 are reduced to slideably engage and guide the cam 249I insliding movement with respect to the collar 253.

A flanged stub shaft 262 (FIGS. 19 and 24) has an approximatelyrectangular ange 263 disposed within the recess 2516 which is ofsufficient dimension lengthwise of the elongated opening 258 to permitmovement of the flange 263 lengthwise of the recess 256. The circularshank 264 of the stub shaft 262 (FIG. 25 slideably extends through theenlarged central portion 259 of the opening 258. The central portion 259is elongated to permit transverse movement of the shank 264 relative tothe collar 253.

The cam 249 has a rightwardly opening slot 266, the lateral edges ofwhich are parallel and disposed at a relatively small acute angle to thecentral axis of the flange 248 and the cam 249. The flange 263 on thestub shaft 262 has a pair of diametrically disposed slots 267 and 268,the inner ends 269 and 270 of said slots being parallel and sloped withrespect to the central axis of the shank 264 at an angle substantiallyidentical with the angle of slope in the lateral edges of the slot 266.The cam 249 and the stub shaft 262 are arranged and nested so that thelateral edges of the slot 266 are slideably engaged with the inner ends269 and 270 of the slots 267 and 268.

The stub shaft 262 is held against axial movement by entrapment betweenthe opposing surfaces of the annular member 238 and the end wall 257.However, the elongation of the recess 256 and the opening 258 permittransverse movement of the stub shaft 262 with respect to the collar253, hence, with respect to the annular member 238, the slide 241 andthe bearing support 230. Thus, when the slide 241 is moved `from itssolid line position to its broken line position in FIG. 19, the stubshaft 262 is moved, due to the inclined plane of engagement between thestub shaft 262 and the cam 249, into a position of eccentricity withrespect to the shaft 168A.

The alternate tu-be cutting head 23A (FIG. 16) includes an elongatedsupport plate 273 having parallel openings therethrough near theopposite ends thereof in which the bearings 274 and 275 are supportedfor rotatable engagement and support upon reduced portions of theShanks, such as the shank 264 of the stub shaft 262, extending from theeccentric mechanisms 233 and 234. The

support plate 273 is held in place on said shanks by the nuts 278.

The cutting head (FIG. 17) has a pair of spaced side plates 281 and 282which are held in spaced relationship with respect to each other bythreaded rods and nuts 283 and spacers 284 through which the threadedrods extend. The entry side plate 281 is rigidly secured to the outputend of the carriage 22A so that the exit side plate 282 is also rigidlwith respect to the carriage 22A. The side plates 281 and 282 (FIG. 18)have elongated recesses 286 and 287 iu their opposing surfaces in whichthe bearing plates 288 and 289 are respectively received and held.

Support plate 273 (FIG. 18) has an elongated opening 292 which isslightly enlarged at the opposite faces of the support plate forreceiving a pair of slide plates 293 and 294 which also serve asretainers for the tool holding insert 296 which is provided with aplurality of tool openings 297 (FIG. 18) aligned lengthwise of theinsert (FIG. 26) and equal in number to the maximum number ot tubeswhich will normally be run through the cutting head at any given time.

A plurality of cylindrical cutting tools 103A (FIG. i8), which arepreferably identical with the above-described tools 103, are snugly butslideably received into the tool openings 297. The slide plates 293 and294 are provided with openings 298 and 299 which are aligned axiallywith the openings 297 and slightly smaller than such openings forholding the tools 103A against axial movement with respect to thesupport plate 273.

The side plate 281 and its corresponding bearing plate 288 have aplurality of tube openings preferably identical with the number` in thetool-holding insert 296 and axially alignable therewith. These openingsdefine a passageway 302 into which a anged guide sleeve 303 is receivedfor guiding a tube 11 (FIG. 1) through the entry side of the cuttinghead 273 (FIG. 18). A similar plurality of passageways 304 are providedin the side plate 282 and bearing plate 289 for reception of sleeves 306for guiding the movement of the tubes 11 through the exit side plate282. The inside diameters of the sleeves 303 and 306 are somewhat largerthan the outside diameter of the tube 11 and, the cutting edge 107A ofeach tool 103A is slightly larger in diameter than the outside diameterof the tube 11 for slideably receiving same therethrough.

From the foregoing description with respect to the alternate cuttinghead 23A, it will be seen that rotation of the shafts 168A and 169A willcause the support plate 273 to move in a circular path whereby thecutting edges 107A of the tools 103A will engage and cut annular groovesin the peripheral surfaces of tubes extending through the cutting headin much the same manner as described above with respect to the cuttinghead 23. It Will also be seen that the shafts 168A and 169A may rotatecontinuously, and the cutting operation will be initiated by effecting aleftward movement of the bearing support 230 whereby the stub shafts 262are moved into positions of eccentricity with respect to the shafts 168Aand 169A, hence, with respect to the tubes extending through the cuttinghead 23A. Thus, the only essential difference between the operation ofthe alternate cutting head 23A and the cutting head 23 concerns the wayin which the eccentric cutting motion is produced and initiated.

Although particular preferred embodiments of the invention have beendescribed above for illustrative purposes, it will be understood thatvariations or modifications of such disclosure, which come within thescope of the appended claims, are fully contemplated.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A method for forming a U-shaped tubular device from an elongatedtubular element comprising the steps:

advancing a length of said elongated tubular element l2 predetermineddistance through and relative to an annular cutting member having aradially inwardly projecting, circular cutting edge of slightly largerdiameter than the outside diameter of said elongated element;

gripping two portions of said elongated element on opposite sides ofsaid cutting member;

causing said cutting member to move relative to said elongated element,while the axes thereof remain substantially parallel, in an eccentricpath around said element;

continuously urging a portion of said cutting edge against the externalsurface of said elongated element, whereby a circular cut is made insaid external surface;

causing said two portions of said element to be urged axially away fromeach other after the cutting of said element has commenced andsubstantially before the cutting edge penetrates said element wherebysaid two portions of said element are separated; and

bending one of said portions into said U-shaped member.

2. A method according to claim 1,

wherein said eccentric movement of said annular member is terminatedshortly after said two portions of said element are separated; and

wherein the part of said cutting edge engaged with said elementcontinuously and rapidly advances along said cutting edge, the mainthrust of the cutting action being in a nonradial direction.

3. A method according to claim 1, including a plurality of adjacentannular cutting members having substantially parallel axes and wherein aplurality of elongated elements are simultaneously and individuallymoved through and relative to each said annular cutting member; and

wherein said annular cutting members are simultaneously movedeccentrically around said elements.

4. An apparatus for cutting an elongated, tubular element into twoseparate portions, the combination comprising:

a base frame having guide means defining a path along which said elementis advanced in an axial direction; drive means adapted to engage saidelement and ad- Vance it along said path;

a cutting head supporting an annular cutting member having an annular,inwardly extending cutting edge substantially coaxial with said path,said cutting edge having a slightly larger inside diameter than theoutside diameter of said element so that said element can be moved alongsaid path through said annular member;

actuating means connected to said cutting head for effecting eccentricmovement of said annular member around said element and continuouslyurging said cutting edge against the radially outer surface of saidelement;

alignment means releasably engageable with said cutting head forpreventing said eccentric movement of said cutting member while saiddrive means is advancing said tubular element through said cuttingmember;

tirst and second gripping means located on opposite sides of saidcutting head and adapted to engage tirst and second portions of saidelement located on opposite sides of said cutting head, said secondgripping means being part of a bending device whereby the portion ofsaid tubular element gripped thereby is bent into a U-shaped form;

means adapted to move said first gripping means axially away from saidsecond stationary gripping means while said actuating means isoperating.

5. An apparatus according to claim 4,

vit/herein Said cutting head has a plurality of adjacent 13 cuttingmembers having substantially parallel axes for simultaneously receivingand cutting a plurality of elongated tubular elements; and

wherein said gripping means engage all of said elongated elements.

6. An apparatus according to claim 4, including:

a pair of spaced and substantially parallel head plates mounted uponsaid frame and intersecting said path substantially perpendicularly;

axially aligned guide openings extending through said head platessubstantially coaxially with said path;

said cutter head including a cutting support member disposed betweensaid head plates for movement in a plane parallel therewith;

said annular cutting member being mounted in said support membersubstantially coaxially with said aligned openings;

mounting means disposed radially outwardly of said cutter supportmember, and resiliently flexible means connecting said cutter supportmember to said mounting means for resiliently positioning said supportmember with respect to said mounting means; and

said actuating means being connected to said mounting means and adaptedto effect an eccentric movement thereof with respect to said path,whereby said cutting edge moves eccentrically around and thereby seversa tubular element extending through the cutter member.

7. An apparatus according to claim y6,

wherein said mounting means is an annulus substantially concentric withsaid path;

wherein said resiliently flexible means comprises a plurality of coilsprings extending substantially radially of said path between saidsupport member and said annulus; wherein said head plates and saidsupport member have aligned openings of substantially the same diameterand spaced radially from said path; and including pin means mounted uponsaid frame for snug reception into said aligned openings, and means foreffecting axial movement of said pin means into said aligned openings toprevent relative movement between said support member and said headplates. 8. An apparatus according to claim 7, wherein said head plateshave plural pairs of axially aligned and axially parallel guideopenings, and wherein an equal number of cutter members are axiallyaligned with said plural pairs, said guide openings and cutter membersbeing arranged close together for simultaneously receiving a pluralityof elongated tubular elements; and plural pin means and plural sets ofaligned openings for receiving said pin means.

References Cited UNITED STATES PATENTS 3,108,819 10/'1963 McKay z82-20X3,154,976 11/1964 Chase 72-67 CHARLES W. LANHAM, Primary Examiner R. M.ROGERS, Assistant Examiner

